Although it has been more than fifty years since DDT was banned, a new study has revealed how the chemical still continues to affect our ecosystem.
In case you didn’t know, back in the middle of 20th century, people started using dichlorodiphenyltrichloroethane or DDT to fight against pest outbreaks across North American forests. During this time, airplanes sprayed onto forests in an attempt to eradicate spruce budworm. While at the time the chemical was sprayed on trees, it made its way to forest waters through rain and natural causes. As the chemical continued to pollute water, it was banned after protests back in 1972. However, the recent study by researchers from McMaster University proved that the effects are still present in our ecosystem.
In the latest study, published in the journal Environmental Science and Technology, researchers collected samples from five remote lakes in Canada. Unsurprisingly, the researchers found elevated amount of DDT in the samples in the layers from 1960s and 70s. However, the current layers of the sediment contain toxins which exceed the amount the threshold for harmful effects. Moreover, the researchers measured the correlation between DDT levels and water populations. Unsurprisingly, they found increased algae production which means fewer prey for fish population in the area.
Karen Kidd, professor at McMaster University noted in an official press release, “We have learned a lot of tough lessons from the heavy use of DDT in agriculture and forestry. The biggest one is that this pesticide was concentrated through food webs to levels that caused widespread raptor declines in North America. The lesson from our study is that pesticide use can result in persistent and permanent changes in aquatic ecosystems.”